How good a preamp is Esoteric D-70 DAC?

I'm considering a D-70 as a DAC + preamp, since it has volume control and a few inputs, and my only sources are digital. It would feed a tubed McIntosh MC275. However I cannot find any comments from people using it in this manner.

I can probably get a P70/D70 combo for $5500 or get...say a McIntosh C220 preamp for $2500 and spend $3000 on a CD player.

Would the D70 sound better than a $2500 (used) preamp?

Thank you!
If you only have digital in, then it would seem that a top quality DAC with volume control is all you need (or want). How can a separate pre-amp and CD player be better? It is just more components in the chain.
You are correct, as long as the volume control implementation is as good as one in a good preamp. This is actually why I'm asking. Have you had the chance to listen to a D70 direct into an amp?